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Joliet, IL

being a very hot year for many growers this year in the midwest, northern plains, down south and out east and way hotter at pollination than many would like, i was wondering if anyone has noticed any correlation to temperature and seeds count. after reading the post by joze on male flowers, i just started thinking about variables and the whole process and this past years' weather. i would think if aborts were a problem due to heat, wouldn't the heat affect the amount of successful seed development. over the years i have just made it a habit to cool the female down with fans 3 days prior and leave the fan on for 3 days after setting no matter what the weather temp is like to prevent aborts. and then the ice jugs go between the fan and blossom at 80 degrees or warmer fust for insurance the day before, the same day, and the day after. and all females are shaded with a small patio table as soon as they show until after they either take or don't take. too many past aborts in the illinois summer heat on prime located females lead to this being standard pollination practice for myself. i think this year was the first year the high heat affected those to the north and east of us way higher than normal and was wondering how many of those micro-climatize around the female at pollination. i got lucky this year and the only 3 days of the summer that seemed to be cloudy and were at or below 80 degrees were june 12th -14th which was earlier than i was looking for, but got lucky with the window none the less. very good seed counts on both pumpkins set on cooler days and had fans on them anyways. just curious to others thoughts and experiences with temperatures at set time and seed count totals.

12/4/2010 4:11:23 PM

Joliet, IL

on a snowy saturday and a little research, i found this paragraph on page 9 of this post.

"High temperatures also seem to have an effect on the seed
set. Pollen viability is affected and its' germination rate
decreases. This results in poor germination (seed
development) and constricted fruit development."


http://www.uky.edu/Ag/IPM/manuals/ipm12pum.pdf

i will keep looking for some more info.

12/4/2010 5:03:25 PM

East Jordan, MI

I have also been speculating that the weather might have had something to do with it, but maybe not at pollination, but during a critical part of seed creation.

As for pollination time, I had 2 pumpkins, pollinated 5 days apart. It was abnormally hot (for this area) during both pollinations. The first one I didn't write down the temp, so think it was less than 85 because I'm pretty sure I would have made a note if it wasn't. It rained more than 5.5 inches in the 5 days prior to and more than 1.5 inches the day after pollination on it. This is the one that the seeds didn't completely mature. I got nearly 50 fully formed ones and 60 that are probably good seeds but with white tips. There were over 200 that were white and paper thin. I also pollinated this one prior to daylight and had to force open the bloom, which was really worrying me at the time as to whether it was ready or not.

The other one the was pollinated when it was hotter (93) but because of that I used ice jugs and a fan for pollination day and the day after and fans for 4 days following that. That pumpkin blew up at 40 days, but had 646 perfect fully formed seeds and less than 10 that weren't pollinated. This one was pollinated on Sat so I was able to wait until after daylight. When I pulled the cup off of it, the bloom sprung open.

After going back and re-reading my notes I believe that the time of pollination probably had more to do with my immature seeds than anything else. But because others in my area that had very low seed counts that have alot more experience with hand pollination, I still have to wonder if the weather also played a roll. We had an extremely hot summer with very little rain.

12/4/2010 5:07:17 PM

Joliet, IL

"High temperatures also have an effect on the seed set due to reduced pollen viability and poor pollen germination leading to early fruit abortions or deformed and unmarketable pumpkins."

http://agdev.anr.udel.edu/weeklycropupdate/?p=1583

with both of these found in 5 minutes, i am sure there is plenty more out there. but in my mind, this info can justify using fans, shading, and ice bottles if needed can not only increase the chancdes ofthe fruit setting, but should help with more seeds setting successfully if the pollen is kept cooler. and also, if heat effects pollen viablitity, i would imagine it would be better to use as many flowers that are available because more pollen would increase the chances of more staying viable.

12/4/2010 5:13:53 PM

Muddy Waters

are you guys pollinating at 68 degrees to 73 degrees that was the rule 10 years ago.has that changed??? just asking.i took about 5 years off a lot has changed.

12/4/2010 5:25:05 PM

East Jordan, MI

Handy,
This is my first year growing AGs so I'm certainly still seeking out what the "right" things to do are. I haven't heard a specific temp recommended for pollination -- until now. Would be interested in hearing more opinions on this subject.

12/5/2010 12:28:55 AM

Rhode Island

weather my friend shazzy as always been talked about as the great equalizer,especially when discussing our pumpkins growth,daily gains,etc.
it certainly makes sence then that it mot only plays a roll during pollination period,but also seed development.
good post shazz
pap

12/5/2010 8:07:37 AM

Rhode Island

a poor mans pollination prep kit . to be used in case of pollination temps in excess of 90 + degrees

1. get out there as early as possible . be sure males are dry
2. bag of ice (place between fan and pollinated pumpkin)----- moms or wifes frozen chicken will do in a pinch.
3. fan at the ready
4. small cheese cloth covering to shade the pollinated fruit
5. say a prayer
pap

12/5/2010 8:16:32 AM

Joliet, IL

i like it pap. bags of ice work good, but a larger chunk of ice takes longer to melt. the laundry detergent bottles filled 3/4s full of water and thrown into the freezer are nice and re-usable. my freezer is completely packed with all different sizes of bottles at pollination time. the hottest days i can't get home to replace the frozen bottle while at work gets the jumbo size ice bottle. i like the frozen chicken idea in a pinch...lol...whatever it takes.

12/5/2010 9:02:42 AM

Going Green

If your gonna tarpthe pumpkin then why not tarp the bloom. Get out there early. sprinkle the ground surrounding the bloom directly after pollination. Set out frozen bottles of water and turn on fan. Now tarp the area with the bloom in the center! Shade the area from the sun with tarp. Cool the ground with water and the air near the bloom with colder air coming from the fan hitting the frozen bottles!

12/5/2010 2:31:19 PM

Muddy Waters

Can you pollinate at 90 degrees I didnt think this was possible????

12/6/2010 11:56:44 AM

Joliet, IL

i have successfully pollinated at 93 degrees with methods detailed on the first post of this thread and had good seed count on that pumpkin. i was only one 1 of 2 on pollinations that day though so it doesn't always work. but these methods have helped me increase my percentages of setting in the high heat since using them. and i am not sure of the correlation, but i always try to use 5 or more flowers up to 9 when pollinating and i have yet to ever have a low seed count. usually at least 400 or higher solid seeds per pumpkin. not sure if it matters, but i like to gently load them up if i can and cover every part of all the lobes repeatedly.

12/6/2010 10:03:02 PM

Deer Park, WI

Shazzy-

Great post. From a physiological point of view, science recognizes that in both humans and plants, the male reproductive vehicles (sperm, pollen) operate most effectively at cooler temperatures.

Ever wonder why human male testicales reside in a sack rather than inside the body? 98.6 degrees, while ideal for the function of normal bodily processes, is too hot for sperm development and maturation. They thrive in a slightly cooler environment that is enabled by their location in the scrotum.

Same temperature principle applies to pollen. Above 85 degrees, the enzymes (chemical reaction catalysts) that facilitate the pollen germination and transport process within the female reproductive organ begin to malfunction. Every process in both the plant and animal kingdom as an ideal temperature at which it operates. Pollination and fertilization are particularily sensitive to this.

Hence, its no surprise Shazz has had positive outcomes in controlling the local environment.

If one wants to maximize the likelihood of a pollination set and seed fertilization, following the advice above is the best way to do so. 65-75 degrees is the sweet spot for maximizing this process.

12/6/2010 10:35:57 PM

Muddy Waters

I learn something new everyday.I thought the window closed at 75 degrees.I have gone to work late to pollinate many times.I know in Mich. flowers open at 68 degrees I have watched it dozens of times.I dont know how you cool such a big plant.Like trying to cool the big toe on a Gorilla.With blood flowing at 98 degrees how you cool all that???Do you lay bags of Ice on fruit??I would think it would be easier to use lites to open flowers at 4 AM when cooler temps are present,has this been tried???? Just asking dumb questions!!!

12/17/2010 6:02:00 AM

Joliet, IL

handy, this method i have used has been out of trial and error over 9 years with the advice of many other growers with similar practices. i think the idea is to keep the pollen cool and the ovule cool. that is a good point about internal plant temps. i would think that similar to joze's reference to the male human and the testicles hanging away from the body to lower the temperature in that region, anything at the place the miracle happens needs to be cool enough to make work so the pollen remain viable and the female doesn't shut down either. from research i have done, the plant is programmed to wait until cooler days because the energy and water intake with a new fruit set stresses the plant that is already stressed from the heat. so it basically waits for the better chances of staying alive to try again on cooler days. the idea is to trick the plant into setting anyways.

your point about cooling the whole plant, i do that also anyways because i have a misting system that i use anytime it gets that hot. just don't get the pollinated female wet.

i think a flower at 4 am is still settable by forcing it open. this is why males and females are covered to prevent any slips in the cracks prior to opening. maybe not a bad idea to force open and pollinate early on really hot days, but i only force open around 6 am when in a pinch with success. not sure how early is too early.

12/17/2010 7:37:10 AM

Western PA

I think I am going to do as shazzy says, using as many males as I can for now on. They are only good for 1 day anyways,so I may as well use them if I got them.

I think brooks b pollinates VERY early in the am. Maybe he will chime in his thoughts on early pollination.

Great post shazzy.

12/17/2010 7:59:42 AM

Saegertown Pa.

I have pollinated between four and five AM and had no proublem.

12/17/2010 9:04:28 AM

I always cut males the evening b4 and bring inside overnight. solving the overheated pollen issue. If I need to use them early in the morning I find setting them under a light (actually on my range top) they will open fully in 30-60 minutes.

As to females and heat I wish I had that problem here 8)

I think in 5 years I have had to cool pollinated females maybe 3-4 times, sad but true.

I always have had good to great seed counts, not that I have grown anything at this point that pushes the sizes some have.

12/17/2010 9:08:32 AM